Unhappy with your render finish? We can help!

We know how disappointing it feels when you’ve paid good money for a job and the end result just isn’t up to scratch. You stand back, have a look… and instead of feeling proud, your heart sinks a bit. Sadly, you’re not alone.

We get quite a few queries from people who have had their properties rendered and are not happy with the finish.

The most common issues we hear about are:

• Hairline cracks or sometimes much larger cracks

• An uneven or patchy finish across the wall

• The render colour not matching expectations

• Algae starting to grow far sooner than expected

• Bubbling or blistering in the render surface

After all, giving your home a facelift isn’t cheap so when the finish lets you down, it can feel pretty devastating. The good news? In most cases, these problems can be fixed properly and we’ll walk you through how.

Cracks Forming in Your Render? Here’s Why It Happens (and How to Fix It Properly)

One of the most common questions we get is:

"Can I just go over the cracked render with a new textured topcoat."

We hate to be the bearer of bad news, but no that won’t solve the problem.

Let’s break it down.

Why a Render Topcoat Alone Won’t Work

Thin-coat renders (like our popular 1.5mm Silicone Silicate Render System) are applied very thinly as the name suggests, around 1.5mm thick. That topcoat is designed to finish a wall, not to fix what’s underneath.

There are two big reasons why applying a topcoat directly over old or cracked render will fail:

1. The wall won’t be flat enough
Textured finishes need a perfectly flat surface to look right. Any dips, bumps or cracks underneath will show through like a bad wallpaper job.

2. It won’t have enough strength
Without a proper base coat, the render simply doesn’t have the reinforcement it needs so cracks will reappear often quicker than you’d expect.

The Right Way to Fix Cracked or Poorly Finished Render

If you want the repair to last (and not be doing this all over again in five years’ time), the solution is:

• A new base coat

• Reinforced with fibreglass mesh 

• Fixed using a high-strength adhesive like EWI-225 Premium Adhesive

• Finished with a Silicone or Mineral render topcoat

We recommend EWI-225 over standard adhesives when going over existing render because it adds that extra bit of robustness exactly what you want when you’re correcting a failed system.

In short: If your render is cracking, painting or thin-coating over it is a short-term fix at best. A reinforced base coat is the only way to solve the issue properly.

Installed correctly, our render-only systems should remain crack-free for a minimum of 10 years.

If your render is newly installed and already cracking, that’s usually a sign of an installation issue and it’s worth getting advice before spending any more money.

Not Happy With the Render Finish or Texture?

Sometimes the issue isn’t cracking, it's simply that the finish looks inconsistent, patchy or rushed. Different textures across the same wall are a common complaint, especially when drying conditions weren’t ideal.

The solution here is much the same:

• A fresh base coat with embedded fibreglass mesh

• Followed by a new render topcoat to give an even, consistent texture

If you’ve already been stung once, the last thing you want is guesswork. We work with a network of approved renderers and external wall insulation installers who know these systems inside out and will do the job properly.

Unhappy With the Colour of Your Render? This One’s Easier to Fix

Now for some good news if the render itself is sound and you simply don’t like the colour, the solution is far simpler (and cheaper).

In most cases, all you need is Silicone Paint.

Why Silicone Paint Works So Well on Render

• Breathable (so moisture can escape)

• Designed specifically for masonry and render

• Can be tinted to suit your design preferences

• Two coats usually does the job even over darker colours

Silicone Paint can be applied to most render types. In some cases, the existing surface may need priming first and if you’re unsure, just give us a call and we’ll point you in the right direction.

Algae Growing on New Render? Unfortunately, It Happens

Seeing algae on a newly rendered wall can be frustrating especially when the work is barely finished.

Some render types are more prone to algae growth than others. Acrylic render, while often chosen because it’s cheaper upfront, is particularly susceptible.

Silicone and Mineral renders are far more resistant, but location matters too. If your house is surrounded by trees, shaded areas or woodland, some algae growth over time is almost inevitable.

How to Reduce the Impact of Algae

• Choose Silicone or Mineral render over Acrylic where possible

• Consider slightly darker colours, which hide light algae better

• If Acrylic render is already installed, apply:

• A new base coat

• Followed by a Silicone render finish

This won’t just improve appearance, it'll also help protect the wall long-term.

Bubbling or Blistering Render? Don’t Ignore It

Bubbling render is often a sign of moisture issues, poor preparation or incompatible materials. Left untreated, it can lead to larger failures down the line.

If you’re seeing bubbling, it’s best to get advice early. A quick assessment can save a lot of hassle (and money) later on.

If you’re concerned that poor insulation-related issues might be contributing to render bubbling, the UK government offers guidance on what to do if you’ve had poor quality external wall insulation installed. See GOV.UK for details on next steps and professional checks.

Unhappy With Your Render Finish? Let’s Fix It Properly

If you’re not happy with how your render looks, you don’t have to live with it and you don’t have to gamble on another quick fix either.

Give us a call or send us a photo of your wall. We’ll help you:

• Identify what’s gone wrong

• Decide whether it needs repairing, recoating or repainting

• Choose the right products for a long-lasting result

No hard sell, just straight advice from people who work with render systems day in, day out.

Let’s get your home looking the way it should have done the first time.

Frequently Asked Questions About Fixing a Bad Render Finish

Can cracked render be repaired, or does it need to be removed?

In most cases, cracked render does not need to be completely removed. The key is understanding why it has cracked. If the underlying render is still well bonded, a new reinforced base coat with fibreglass mesh, followed by a suitable render topcoat, will usually solve the issue long-term. Simply painting or thin-coating over cracks will almost always result in them coming back.

How long should render last before problems appear?

A properly installed render system should last 10–25 years or more before any major issues arise. If cracking, bubbling or discolouration appears within the first few years, it’s usually down to poor preparation, incorrect materials, or installation errors rather than natural ageing.

Can I paint over render instead of re-rendering?

Yes, if the render itself is sound. If you’re unhappy with the colour but the surface is intact, breathable Silicone Paint is often the most cost-effective solution. However, paint will not fix cracks, uneven textures or bubbling render.

Why is algae growing on my new render?

Algae growth is influenced by both render type and environment. Acrylic renders are more prone to algae, while Silicone and Mineral renders resist it far better. Shaded areas, nearby trees and damp conditions all increase the likelihood of growth, even on higher-quality renders.

Is bubbling render a serious problem?

Bubbling or blistering render shouldn’t be ignored. It often points to trapped moisture, poor adhesion or incompatible materials. Left untreated, bubbling areas can lead to sections of render failing altogether, so it’s best to get advice early.

Do I need a specialist to fix the failed render?

Yes,  render systems are layered and technical, and small mistakes can lead to failure down the line. Using experienced renderers who understand the full system, rather than just the finish coat, makes all the difference. We’re happy to advise or recommend approved installers.

Not sure what’s gone wrong with your render?

If you’re unsure whether your render needs repairing, repainting or replacing, send us a photo or give us a call. We’ll help you figure out the best next step  and avoid unnecessary costs.